Facsimile machines and other data handling customer premise equipment are introduced not only into offices but individual homes in great numbers. As personal computers are found in more homes, users of computer networks such as "Internet" by way of telephone networks through modems are increasing in phenomenal numbers. The majority of these data transactions through modems or fax machines use existing local exchange carrier networks for data transmission. Fax machines, computers, and telephone sets at a customer premise are connected by local access to a central telephone switching office. Local access is variously called a subscriber's loop, local loop, drop etc. In cases of CATV or wireless, local access is also called subscriber connection, wireless access etc. It has been shown that the majority access "Internet" by dial-up telephone connection.
FIG. 1 shows how a telephone, fax, computer and other intelligent agents are typically connected through a publicly switched telephone network and data networks and their interconnections. Terminal equipment at a customer premise consist of a telephone set, fax machine, a personal computer etc., and are collectively called CPE which stands for customer premise equipment. CPE 10 is connected through inside wiring 12 at the customer premise and then through the feeder/distribution plant (also called subscriber's loop, local access loop) 14 to an access module (e.g. linecard) 16. The linecard is in turn connected to a local switch 18 that is part of the public switched telephone network (PSTN) 20. PSTN operates in channelized mode and provides continuous connection to another subscriber 22. The telephone service is established through a connection protocol (e.g. dialup, on-hook/off-hook protocol) and upon connection provides fixed channelized bandwidth on a continuous basis for the duration of the call. A facsimile connection is essentially the same as a telephone connection with the exception of the presence of a modem 24 at each facsimile terminal. The figure also shows a connection involving a data network. For such a connection, the CPE (e.g. computer) also requires a telephone subscriber's loop to the PSTN by dialup service which connects to a data service provider 26 through its own subscriber's loop 28. The data service provider 26 then provides a data connection through a data network 30 to a database service or other data service subscribers.
Computer connections are generally much longer in duration than voice or other connections. Computers perform data transactions in packets and their traffic is very bursty. The bursty traffic is more suitable for statistical multiplexing and is most efficiently handled by specially designed data networks such as packet switched networks. At present, however, all publicly switched traffic, data and voice, is sent over the subscriber's loop and interoffice trunking in a circuit switched network connection to destination customer premise equipment or to a data network.
Multimedia broadband switched networks by the name of the "Information Superhighway" have been widely proposed. This superhighway may carry different types of traffic seamlessly, accepting voice, data and video information from any terminal and delivering it to any other terminals simultaneously. At present, however, different types of networks, both channelized and packetized, exist separately and independently.
In circuit switched networks, a connection is maintained during the whole duration of a call through switches and other associated network elements, regardless of the type of the call. Only one circuit switched connection can be maintained for the call. No broadcast or multicast through the circuit switched network is possible. Today, telephone networks are becoming increasingly more occupied by data traffic which generates no additional revenues to the local exchange carriers. Furthermore, access to worldwide computer networks, such as "Internet" etc. is now being provided by commercial network service providers, such as "America Online", "SprintLink" etc. Using PSTN as the access, the network service providers provide access to various other private networks, academic networks etc., which contain vast numbers of databases for value added services.
FIG. 2 shows diagrammatically how data networks such as "Internet" are accessed through a telephone subscriber's loop. An individual end user subscribes to the service of a commercial network service provider 40. Access to a data network is usually by dialling the telephone number of a commercial data network service provider using a modem. Thus the end user CPE 42 uses a modem and makes a dialup connection to a local switch 44 by a subscriber's loop 46. The local switch 44 makes an inter-office trunk connection 48 to a terminating local switch 50 within a PSTN 52. The terminating local switch connects through a local loop 54 and a terminating modem to a service provider 40. After a proper modem handshaking protocol, the user inputs the address of a destination such as the "Internet" server with whom he desires a connection. Data networks and database services are accessed using a TCP/IP protocol. The "Internet" packet is routed over a T-1 link 56 (or other facilities) to the Internet 58. In this arrangement, the local switches 44 and 50 as well as the interoffice trunk 48 are occupied for the duration of the connection, which is usually measured in hours rather than the shorter holding time associated with voice calls which are measured in minutes. Consequently, very expensive common equipment in the PSTN is required for the duration of the "Internet" access, even during a period of inactivity by the end user.
The use of a telephone network by network service users increases usage of the telephone network enormously without a proportionate increase of additional revenues to the telephone company. It is also cumbersome for an individual user to access various networks. It will be shown below that the present invention reduces this investment in the PSTN as well as enhances the capabilities of the overall global communications network.
The U.S. Pat. No. 5,610,910, filed on Aug. 17, 1995 and issued on Mar. 11, 1997 having a common inventor, describes a new access architecture which improves the access to telecommunications networks including various different types of networks. It involves a local access which determines the kind of service requested by a connection request and selects access directly to the network requested or a network which is decided upon preset conditions.
The present invention expands on this access architecture and is directed to a novel implementation which allows efficient use by data and voice traffic of available bandwidth between CPEs and the telecommunications network in an ISDN-like environment.